In recent years, aircraft and ships have been growing in size. Consequently, once an accident occurs, there can be a large number of victims. In particular, if an accident occurs on, in, or above a sea, lake, river or the like, there can be a large number of people who need to be rescued (hereinafter referred to as rescuees). Besides, swollen rivers and inundated regions caused by a natural disaster such as a heavy rain, typhoon, tsunami, or the like also produce rescuees. A search and rescue operation by a helicopter from the sky is especially effective in saving such rescuees.
Therefore, a rescue method has conventionally been available, as described in Patent Literature 1, in which a rope is thrown from a helicopter, allowing a rescuee to catch the rope, and a rescuer approaches the rescuee by water or descends from the helicopter to save the rescuee. Also, there is a method, as described in Patent Literature 2, which involves dropping a circular escape bag containing a rescue net thereinside from a helicopter and saving any rescuee caught in the rescue net.
However, there is a problem that with either method, coverage of rescue operations is extremely limited, and when there is a severe storm or high waves, it is very difficult to drop a rope or escape bag in a rescuable range for rescuees, making it sometimes impossible for the rescuee to reach the rescue device, and consequently rendering the rescue device useless.